Buggy code:
public class Main { protected ClassLoader classLoader ; protected String driver ; protected String username ; protected String password ; protected String url ; protected String databaseClass ; protected String defaultSchemaName ; protected String changeLogFile ; protected String classpath ; protected String contexts ; protected String driverPropertiesFile ; protected Boolean promptForNonLocalDatabase = null ; protected Boolean includeSystemClasspath ; protected String defaultsFile = "liquibase.properties" ; protected String diffTypes ; protected String changeSetAuthor ; protected String changeSetContext ; protected String dataDir ; protected String referenceDriver ; protected String referenceUrl ; protected String referenceUsername ; protected String referencePassword ; protected String currentDateTimeFunction ; protected String command ; protected Set < String > commandParams = new LinkedHashSet < String > ( ) ; protected String logLevel ; protected String logFile ; protected Map < String , Object > changeLogParameters = new HashMap < String , Object > ( ) ; public static void main ( String [ ] args ) throws IOException , CommandLineParsingException { } private static String generateLogLevelWarningMessage ( ) { } protected String [ ] fixupArgs ( String [ ] args ) { } protected List < String > checkSetup ( ) { List < String > messages = new ArrayList < String > ( ) ; if ( ( command ) == null ) { messages . add ( "Command<seq2seq4repair_space>not<seq2seq4repair_space>passed" ) ; } else if ( ! ( isCommand ( command ) ) ) { messages . add ( ( "Unknown<seq2seq4repair_space>command:<seq2seq4repair_space>" + ( command ) ) ) ; } else { if ( ( url ) == null ) { messages . add ( "--url<seq2seq4repair_space>is<seq2seq4repair_space>required" ) ; } if ( ( isChangeLogRequired ( command ) ) && ( ( changeLogFile ) == null ) ) { <START_BUG> messages . add ( "--changeLog<seq2seq4repair_space>is<seq2seq4repair_space>required" ) ; <END_BUG> } if ( ( isNoArgCommand ( command ) ) && ( ! ( commandParams . isEmpty ( ) ) ) ) { messages . add ( ( "unexpected<seq2seq4repair_space>command<seq2seq4repair_space>parameters:<seq2seq4repair_space>" + ( commandParams ) ) ) ; } else { checkForUnexpectedCommandParameter ( messages ) ; } } return messages ; } private void checkForUnexpectedCommandParameter ( List < String > messages ) { } private boolean isChangeLogRequired ( String command ) { } private boolean isCommand ( String arg ) { } private boolean isNoArgCommand ( String arg ) { } protected void parsePropertiesFile ( InputStream propertiesInputStream ) throws IOException , CommandLineParsingException { } protected void printHelp ( List < String > errorMessages , PrintStream stream ) { } protected void printWarning ( List < String > warningMessages , PrintStream stream ) { } protected void printHelp ( PrintStream stream ) { } public Main ( ) { } protected void parseOptions ( String [ ] args ) throws CommandLineParsingException { } private String [ ] splitArg ( String arg ) throws CommandLineParsingException { } protected void applyDefaults ( ) { } protected void configureClassLoader ( ) throws CommandLineParsingException { } private void addWarFileClasspathEntries ( File classPathFile , List < URL > urls ) throws IOException { } private File extract ( JarFile jar , JarEntry entry ) throws IOException { } protected void doMigration ( ) throws Exception { } private String getCommandParam ( String paramName ) throws CommandLineParsingException { } private Database createReferenceDatabaseFromCommandParams ( Set < String > commandParams ) throws CommandLineParsingException , DatabaseException { } private Writer getOutputWriter ( ) { } public boolean isWindows ( ) { } }

Fix:
messages . add ( "--changeLogFile<seq2seq4repair_space>is<seq2seq4repair_space>required" ) ;